Zoo li helicaliav sab hauv Feem ntau yuav tsum tau hloov kho profile thiab qhov tseeb yog ISO6-7, ua ntej txhua qhov kev thauj khoom, peb yuav muab cov ntawv qhia hauv qab no rau cov neeg siv khoom los xyuas cov ntsiab lus ntawm lub nplhaib helical iav kom paub tseeb tias txhua tus to taub meej thiab zoo rau nkoj.

1) npuas kos duab

2)Dtsab ntawv ceeb toom

3)Hnoj cov ntaub ntawv kho mob ua ntej kev kho cua sov

4)Hnoj cov ntaub ntawv kho mob tom qab kho cua sov

5)Mtsab ntawv ceeb toom

6)Aqhia tseeb

7)Picctures thiab tag nrho cov yeeb yaj duab sim xws li runout, Cylindricity thiab lwm yam

8) Lwm cov ntaub ntawv ntsuam xyuas raws li cov neeg siv khoom xav tau xws li daim ntawv ceeb toom tsis txaus ntseeg